I have been watching New York&rsquo;s 1st district since I came to Washington, D.C., in 1980.

The suburban district on the east end of Long Island has often had competitive races and has flipped from one party to the other a number of times during the past 30 years.

I saw incumbent Bill Carney (R) win re-election that November, and I watched George Hochbrueckner (D) win the seat when Carney retired four years later. I saw Republican Michael Forbes beat Hochbrueckner in 1994, and I watched Forbes switch parties and then lose his bid for the Democratic nomination in 2000.

Later that same year, I saw Republican Felix Grucci win the open seat, and only two years later, I saw Grucci lose to Democrat Tim Bishop. And in 2010, I watched Bishop win re-election against GOP challenger Randy Altschuler by just 593 votes in one of the closest outcomes in the country.

That history is why I was surprised by a July 17-18 Garin-Hart-Yang survey for the House Majority PAC, a Democratic super PAC, that showed Bishop leading Altschuler by a stunning 24 points, 56 percent to 32 percent, in this year&rsquo;s rematch.

It&rsquo;s not that the five-term Bishop shouldn&rsquo;t have a slight advantage this year. He survived the 2010 GOP wave, so it isn&rsquo;t unreasonable to think that he is more likely than not to survive again (which is why my newsletter rates the race as Tossup/Tilt Democratic). But a 24-point lead?

Not surprisingly, I had to wait only a few days until Altschuler started crowing about the results of his new poll, conducted by Pulse Opinion Research, which uses &ldquo;automated polling methodology and procedures licensed from Rasmussen Reports, LLC.&rdquo;

The survey showed Altschuler leading Bishop by 4 points, 47 percent to 43 percent. That&rsquo;s not impossible. But the survey also showed presumptive GOP presidential nominee Mitt Romney ahead of President Barack Obama 54 percent to 40 percent in the district, which is very hard to believe.

Obama beat Sen. John McCain (R-Ariz.) in the district by about 3 points in 2008, 51 percent to 48 percent, so it&rsquo;s certainly possible that Obama would trail in the district by a point or two now. But a 14-point lead and Obama drawing only 40 percent?

So, I&rsquo;m stuck with two very different surveys. What should I believe?

Let&rsquo;s start with the polls themselves. The Democratic survey is a traditional poll conducted by a respected polling firm. The GOP survey is an automated survey conducted by a polling firm without much of a track record and appears to be connected with Rasmussen Research, a GOP firm that is not usually included in a list of the most respected survey firms.

Interestingly, Pulse Opinion Research isn&rsquo;t Altschuler&rsquo;s regular polling firm. John McLaughlin of McLaughlin &amp; Associates, an established GOP firm, did the Republican hopeful&rsquo;s polling last cycle and will do it again this year. My guess is that when the Altschuler campaign saw the House Majority PAC survey, it decided to do what most insiders refer to as a &ldquo;quick and dirty survey&rdquo; to rebut the Democratic poll.

While the Pulse Opinion Research poll showed Romney leading in the presidential race in the 1st district by 14 points, Garin-Hart-Yang had Obama up by 5 points, 49 percent to 44 percent.

Given where the presidential race is nationally and how the district voted four years ago, I would expect current polling to show something from a small Obama lead to a small Romney lead. The president&rsquo;s lead in the House Majority PAC might be a few points too big, but it&rsquo;s probably a better reflection of the competitiveness of the race than the Pulse Opinion Research survey.

The two surveys also had different results on Bishop&rsquo;s and Altschuler&rsquo;s name identification.

Even though Altschuler and Bishop ran against each other in 2010, it&rsquo;s hard to believe that about 90 percent of likely voters now have an opinion of both men, as the GOP survey showed. And after the bitter race last time, it seems unlikely that both candidates would have favorable ratings of more than 50 percent.

Which survey should you believe? I can&rsquo;t be sure, so I tend to fall back on the district&rsquo;s fundamentals and look for reasons the 2012 vote might be different from the results of two years ago.

Maybe Suffolk County is changing. After all, less than a year ago, Babylon Town Supervisor Steve Bellone (D) defeated Republican nominee Angie Carpenter, the county&rsquo;s treasurer, to become the new Suffolk County executive.

But it&rsquo;s always wise not to read too much into a local election. Bellone, 42, outspent his 68-year-old GOP opponent heavily, and Carpenter wasn&rsquo;t regarded as a strong candidate. And Bellone&rsquo;s record in Babylon of cutting taxes and cutting town employees isn&rsquo;t particularly identified with the national Democratic Party.

There is one obvious way the 2012 contest differs significantly from the 2010 race, but it benefits Altschuler.

Bishop was the Independence Party nominee in 2010, and he earned 7,370 votes on its line. But this year, Altschuler is the Independence Party nominee, and that development alters the 2010 baseline vote for the two candidates and changes the arithmetic of the 2012 race.

Certainly a presidential year electorate is different from a midterm electorate, especially a Republican wave midterm electorate. But, considering the weakness of the national economy, will the different electorate benefit Bishop or Altschuler? While Obama won the 1st district narrowly in 2008, he isn&rsquo;t likely to do as well this year.

The bottom line? Obama carried the district with 51 percent four years ago. Bishop won by 593 votes last time. Altschuler locked up the GOP nomination earlier this time than he did two years ago.

In other words, no matter what various polls now show, you don&rsquo;t have to go far out on a limb to expect a close race in New York&rsquo;s 1st district in November.